from ctypes import *
from .base import FontException
import pyglet.lib

_libfreetype = pyglet.lib.load_library('freetype')

_font_data = {}


def _get_function(name, argtypes, rtype):
    try:
        func = getattr(_libfreetype, name)
        func.argtypes = argtypes
        func.restype = rtype
        return func
    except AttributeError as e:
        raise ImportError(e)


FT_Byte = c_char
FT_Bytes = POINTER(FT_Byte)
FT_Char = c_byte
FT_Int = c_int
FT_UInt = c_uint
FT_Int16 = c_int16
FT_UInt16 = c_uint16
FT_Int32 = c_int32
FT_UInt32 = c_uint32
FT_Int64 = c_int64
FT_UInt64 = c_uint64
FT_Short = c_short
FT_UShort = c_ushort
FT_Long = c_long
FT_ULong = c_ulong
FT_Bool = c_char
FT_Offset = c_size_t
# FT_PtrDist = ?
FT_String = c_char
FT_String_Ptr = c_char_p
FT_Tag = FT_UInt32
FT_Error = c_int
FT_Fixed = c_long
FT_Pointer = c_void_p
FT_Pos = c_long


class FT_Vector(Structure):
    _fields_ = [
        ('x', FT_Pos),
        ('y', FT_Pos)
    ]


class FT_BBox(Structure):
    _fields_ = [
        ('xMin', FT_Pos),
        ('yMin', FT_Pos),
        ('xMax', FT_Pos),
        ('yMax', FT_Pos)
    ]


class FT_Matrix(Structure):
    _fields_ = [
        ('xx', FT_Fixed),
        ('xy', FT_Fixed),
        ('yx', FT_Fixed),
        ('yy', FT_Fixed)
    ]

FT_FWord = c_short
FT_UFWord = c_ushort
FT_F2Dot14 = c_short


class FT_UnitVector(Structure):
    _fields_ = [
        ('x', FT_F2Dot14),
        ('y', FT_F2Dot14),
    ]

FT_F26Dot6 = c_long


class FT_Data(Structure):
    _fields_ = [
        ('pointer', POINTER(FT_Byte)),
        ('length', FT_Int),
    ]

FT_Generic_Finalizer = CFUNCTYPE(None, (c_void_p))


class FT_Generic(Structure):
    _fields_ = [
        ('data', c_void_p),
        ('finalizer', FT_Generic_Finalizer)
    ]


class FT_Bitmap(Structure):
    _fields_ = [
        ('rows', c_uint),
        ('width', c_uint),
        ('pitch', c_int),
        ('buffer', POINTER(c_ubyte)),
        ('num_grays', c_short),
        ('pixel_mode', c_ubyte),
        ('palette_mode', c_ubyte),
        ('palette', c_void_p),
    ]

FT_PIXEL_MODE_NONE = 0
FT_PIXEL_MODE_MONO = 1
FT_PIXEL_MODE_GRAY = 2
FT_PIXEL_MODE_GRAY2 = 3
FT_PIXEL_MODE_GRAY4 = 4
FT_PIXEL_MODE_LCD = 5
FT_PIXEL_MODE_LCD_V = 6
FT_PIXEL_MODE_BGRA = 7


class FT_LibraryRec(Structure):
    _fields_ = [
        ('dummy', c_int),
    ]

    def __del__(self):
        global _library
        try:
            print('FT_LibraryRec.__del__')
            FT_Done_FreeType(byref(self))
            _library = None
        except:
            pass
FT_Library = POINTER(FT_LibraryRec)


class FT_Bitmap_Size(Structure):
    _fields_ = [
        ('height', c_ushort),
        ('width', c_ushort),
        ('size', c_long),
        ('x_ppem', c_long),
        ('y_ppem', c_long),
    ]


class FT_Glyph_Metrics(Structure):
    _fields_ = [
        ('width', FT_Pos),
        ('height', FT_Pos),

        ('horiBearingX', FT_Pos),
        ('horiBearingY', FT_Pos),
        ('horiAdvance', FT_Pos),

        ('vertBearingX', FT_Pos),
        ('vertBearingY', FT_Pos),
        ('vertAdvance', FT_Pos),
    ]

    def dump(self):
        for (name, type) in self._fields_:
            print('FT_Glyph_Metrics', name, repr(getattr(self, name)))

FT_Glyph_Format = c_ulong


def FT_IMAGE_TAG(tag):
    return (ord(tag[0]) << 24) | (ord(tag[1]) << 16) | (ord(tag[2]) << 8) | ord(tag[3])

FT_GLYPH_FORMAT_NONE = 0
FT_GLYPH_FORMAT_COMPOSITE = FT_IMAGE_TAG('comp')
FT_GLYPH_FORMAT_BITMAP = FT_IMAGE_TAG('bits')
FT_GLYPH_FORMAT_OUTLINE = FT_IMAGE_TAG('outl')
FT_GLYPH_FORMAT_PLOTTER = FT_IMAGE_TAG('plot')


class FT_Outline(Structure):
    _fields_ = [
        ('n_contours', c_short),      # number of contours in glyph
        ('n_points', c_short),        # number of points in the glyph
        ('points', POINTER(FT_Vector)),  # the outline's points
        ('tags', c_char_p),            # the points flags
        ('contours', POINTER(c_short)),  # the contour end points
        ('flags', c_int),             # outline masks
    ]


FT_SubGlyph = c_void_p


class FT_GlyphSlotRec(Structure):
    _fields_ = [
        ('library', FT_Library),
        ('face', c_void_p),
        ('next', c_void_p),
        ('reserved', FT_UInt),
        ('generic', FT_Generic),

        ('metrics', FT_Glyph_Metrics),
        ('linearHoriAdvance', FT_Fixed),
        ('linearVertAdvance', FT_Fixed),
        ('advance', FT_Vector),

        ('format', FT_Glyph_Format),

        ('bitmap', FT_Bitmap),
        ('bitmap_left', FT_Int),
        ('bitmap_top', FT_Int),

        ('outline', FT_Outline),
        ('num_subglyphs', FT_UInt),
        ('subglyphs', FT_SubGlyph),

        ('control_data', c_void_p),
        ('control_len', c_long),

        ('lsb_delta', FT_Pos),
        ('rsb_delta', FT_Pos),

        ('other', c_void_p),

        ('internal', c_void_p),
    ]
FT_GlyphSlot = POINTER(FT_GlyphSlotRec)


class FT_Size_Metrics(Structure):
    _fields_ = [
        ('x_ppem', FT_UShort),    # horizontal pixels per EM
        ('y_ppem', FT_UShort),    # vertical pixels per EM

        ('x_scale', FT_Fixed),     # two scales used to convert font units
        ('y_scale', FT_Fixed),     # to 26.6 frac. pixel coordinates

        ('ascender', FT_Pos),    # ascender in 26.6 frac. pixels
        ('descender', FT_Pos),   # descender in 26.6 frac. pixels
        ('height', FT_Pos),      # text height in 26.6 frac. pixels
        ('max_advance', FT_Pos), # max horizontal advance, in 26.6 pixels
    ]


class FT_SizeRec(Structure):
    _fields_ = [
        ('face', c_void_p),
        ('generic', FT_Generic),
        ('metrics', FT_Size_Metrics),
        ('internal', c_void_p),
    ]
FT_Size = POINTER(FT_SizeRec)


class FT_FaceRec(Structure):
    _fields_ = [
          ('num_faces', FT_Long),
          ('face_index', FT_Long),

          ('face_flags', FT_Long),
          ('style_flags', FT_Long),

          ('num_glyphs', FT_Long),

          ('family_name', FT_String_Ptr),
          ('style_name', FT_String_Ptr),

          ('num_fixed_sizes', FT_Int),
          ('available_sizes', POINTER(FT_Bitmap_Size)),

          ('num_charmaps', FT_Int),
          ('charmaps', c_void_p),

          ('generic', FT_Generic),

          ('bbox', FT_BBox),

          ('units_per_EM', FT_UShort),
          ('ascender', FT_Short),
          ('descender', FT_Short),
          ('height', FT_Short),

          ('max_advance_width', FT_Short),
          ('max_advance_height', FT_Short),

          ('underline_position', FT_Short),
          ('underline_thickness', FT_Short),

          ('glyph', FT_GlyphSlot),
          ('size', FT_Size),
          ('charmap', c_void_p),

          ('driver', c_void_p),
          ('memory', c_void_p),
          ('stream', c_void_p),

          ('sizes_list', c_void_p),

          ('autohint', FT_Generic),
          ('extensions', c_void_p),
          ('internal', c_void_p),
    ]

    def dump(self):
        for (name, type) in self._fields_:
            print('FT_FaceRec', name, repr(getattr(self, name)))

    def has_kerning(self):
        return self.face_flags & FT_FACE_FLAG_KERNING
FT_Face = POINTER(FT_FaceRec)


# face_flags values
FT_FACE_FLAG_SCALABLE          = 1 <<  0
FT_FACE_FLAG_FIXED_SIZES       = 1 <<  1
FT_FACE_FLAG_FIXED_WIDTH       = 1 <<  2
FT_FACE_FLAG_SFNT              = 1 <<  3
FT_FACE_FLAG_HORIZONTAL        = 1 <<  4
FT_FACE_FLAG_VERTICAL          = 1 <<  5
FT_FACE_FLAG_KERNING           = 1 <<  6
FT_FACE_FLAG_FAST_GLYPHS       = 1 <<  7
FT_FACE_FLAG_MULTIPLE_MASTERS  = 1 <<  8
FT_FACE_FLAG_GLYPH_NAMES       = 1 <<  9
FT_FACE_FLAG_EXTERNAL_STREAM   = 1 << 10
FT_FACE_FLAG_HINTER            = 1 << 11

FT_STYLE_FLAG_ITALIC = 1
FT_STYLE_FLAG_BOLD = 2


(FT_RENDER_MODE_NORMAL,
 FT_RENDER_MODE_LIGHT,
 FT_RENDER_MODE_MONO,
 FT_RENDER_MODE_LCD,
 FT_RENDER_MODE_LCD_V) = range(5)


def FT_LOAD_TARGET_(x):
    return (x & 15) << 16

FT_LOAD_TARGET_NORMAL = FT_LOAD_TARGET_(FT_RENDER_MODE_NORMAL)
FT_LOAD_TARGET_LIGHT = FT_LOAD_TARGET_(FT_RENDER_MODE_LIGHT)
FT_LOAD_TARGET_MONO = FT_LOAD_TARGET_(FT_RENDER_MODE_MONO)
FT_LOAD_TARGET_LCD = FT_LOAD_TARGET_(FT_RENDER_MODE_LCD)
FT_LOAD_TARGET_LCD_V = FT_LOAD_TARGET_(FT_RENDER_MODE_LCD_V)

(FT_PIXEL_MODE_NONE,
 FT_PIXEL_MODE_MONO,
 FT_PIXEL_MODE_GRAY,
 FT_PIXEL_MODE_GRAY2,
 FT_PIXEL_MODE_GRAY4,
 FT_PIXEL_MODE_LCD,
 FT_PIXEL_MODE_LCD_V) = range(7)


def f16p16_to_float(value):
    return float(value) / (1 << 16)


def float_to_f16p16(value):
    return int(value * (1 << 16))


def f26p6_to_float(value):
    return float(value) / (1 << 6)


def float_to_f26p6(value):
    return int(value * (1 << 6))


class FreeTypeError(FontException):
    def __init__(self, message, errcode):
        self.message = message
        self.errcode = errcode

    def __str__(self):
        return '%s: %s (%s)'%(self.__class__.__name__, self.message,
            self._ft_errors.get(self.errcode, 'unknown error'))

    @classmethod
    def check_and_raise_on_error(cls, errcode):
        if errcode != 0:
            raise cls(None, errcode)

    _ft_errors = {
        0x00: "no error" ,
        0x01: "cannot open resource" ,
        0x02: "unknown file format" ,
        0x03: "broken file" ,
        0x04: "invalid FreeType version" ,
        0x05: "module version is too low" ,
        0x06: "invalid argument" ,
        0x07: "unimplemented feature" ,
        0x08: "broken table" ,
        0x09: "broken offset within table" ,
        0x10: "invalid glyph index" ,
        0x11: "invalid character code" ,
        0x12: "unsupported glyph image format" ,
        0x13: "cannot render this glyph format" ,
        0x14: "invalid outline" ,
        0x15: "invalid composite glyph" ,
        0x16: "too many hints" ,
        0x17: "invalid pixel size" ,
        0x20: "invalid object handle" ,
        0x21: "invalid library handle" ,
        0x22: "invalid module handle" ,
        0x23: "invalid face handle" ,
        0x24: "invalid size handle" ,
        0x25: "invalid glyph slot handle" ,
        0x26: "invalid charmap handle" ,
        0x27: "invalid cache manager handle" ,
        0x28: "invalid stream handle" ,
        0x30: "too many modules" ,
        0x31: "too many extensions" ,
        0x40: "out of memory" ,
        0x41: "unlisted object" ,
        0x51: "cannot open stream" ,
        0x52: "invalid stream seek" ,
        0x53: "invalid stream skip" ,
        0x54: "invalid stream read" ,
        0x55: "invalid stream operation" ,
        0x56: "invalid frame operation" ,
        0x57: "nested frame access" ,
        0x58: "invalid frame read" ,
        0x60: "raster uninitialized" ,
        0x61: "raster corrupted" ,
        0x62: "raster overflow" ,
        0x63: "negative height while rastering" ,
        0x70: "too many registered caches" ,
        0x80: "invalid opcode" ,
        0x81: "too few arguments" ,
        0x82: "stack overflow" ,
        0x83: "code overflow" ,
        0x84: "bad argument" ,
        0x85: "division by zero" ,
        0x86: "invalid reference" ,
        0x87: "found debug opcode" ,
        0x88: "found ENDF opcode in execution stream" ,
        0x89: "nested DEFS" ,
        0x8A: "invalid code range" ,
        0x8B: "execution context too long" ,
        0x8C: "too many function definitions" ,
        0x8D: "too many instruction definitions" ,
        0x8E: "SFNT font table missing" ,
        0x8F: "horizontal header (hhea, table missing" ,
        0x90: "locations (loca, table missing" ,
        0x91: "name table missing" ,
        0x92: "character map (cmap, table missing" ,
        0x93: "horizontal metrics (hmtx, table missing" ,
        0x94: "PostScript (post, table missing" ,
        0x95: "invalid horizontal metrics" ,
        0x96: "invalid character map (cmap, format" ,
        0x97: "invalid ppem value" ,
        0x98: "invalid vertical metrics" ,
        0x99: "could not find context" ,
        0x9A: "invalid PostScript (post, table format" ,
        0x9B: "invalid PostScript (post, table" ,
        0xA0: "opcode syntax error" ,
        0xA1: "argument stack underflow" ,
        0xA2: "ignore" ,
        0xB0: "`STARTFONT' field missing" ,
        0xB1: "`FONT' field missing" ,
        0xB2: "`SIZE' field missing" ,
        0xB3: "`CHARS' field missing" ,
        0xB4: "`STARTCHAR' field missing" ,
        0xB5: "`ENCODING' field missing" ,
        0xB6: "`BBX' field missing" ,
        0xB7: "`BBX' too big" ,
    }


def _get_function_with_error_handling(name, argtypes, rtype):
    func = _get_function(name, argtypes, rtype)
    def _error_handling(*args, **kwargs):
        err = func(*args, **kwargs)
        FreeTypeError.check_and_raise_on_error(err)
    return _error_handling


FT_LOAD_RENDER = 0x4

FT_Init_FreeType = _get_function_with_error_handling('FT_Init_FreeType',
    [POINTER(FT_Library)], FT_Error)
FT_Done_FreeType = _get_function_with_error_handling('FT_Done_FreeType',
    [FT_Library], FT_Error)

FT_New_Face = _get_function_with_error_handling('FT_New_Face',
    [FT_Library, c_char_p, FT_Long, POINTER(FT_Face)], FT_Error)
FT_Done_Face = _get_function_with_error_handling('FT_Done_Face',
    [FT_Face], FT_Error)
FT_Reference_Face = _get_function_with_error_handling('FT_Reference_Face',
    [FT_Face], FT_Error)
FT_New_Memory_Face = _get_function_with_error_handling('FT_New_Memory_Face',
    [FT_Library, POINTER(FT_Byte), FT_Long, FT_Long, POINTER(FT_Face)], FT_Error)

FT_Set_Char_Size = _get_function_with_error_handling('FT_Set_Char_Size',
    [FT_Face, FT_F26Dot6, FT_F26Dot6, FT_UInt, FT_UInt], FT_Error)
FT_Set_Pixel_Sizes = _get_function_with_error_handling('FT_Set_Pixel_Sizes',
    [FT_Face, FT_UInt, FT_UInt], FT_Error)
FT_Load_Glyph = _get_function_with_error_handling('FT_Load_Glyph',
    [FT_Face, FT_UInt, FT_Int32], FT_Error)
FT_Get_Char_Index = _get_function_with_error_handling('FT_Get_Char_Index',
    [FT_Face, FT_ULong], FT_Error)
FT_Load_Char = _get_function_with_error_handling('FT_Load_Char',
    [FT_Face, FT_ULong, FT_Int32], FT_Error)
FT_Get_Kerning = _get_function_with_error_handling('FT_Get_Kerning',
    [FT_Face, FT_UInt, FT_UInt, FT_UInt, POINTER(FT_Vector)], FT_Error)

# SFNT interface

class FT_SfntName(Structure):
    _fields_ = [
        ('platform_id', FT_UShort),
        ('encoding_id', FT_UShort),
        ('language_id', FT_UShort),
        ('name_id', FT_UShort),
        ('string', POINTER(FT_Byte)),
        ('string_len', FT_UInt)
    ]

FT_Get_Sfnt_Name_Count = _get_function('FT_Get_Sfnt_Name_Count',
    [FT_Face], FT_UInt)
FT_Get_Sfnt_Name = _get_function_with_error_handling('FT_Get_Sfnt_Name',
    [FT_Face, FT_UInt, POINTER(FT_SfntName)], FT_Error)

TT_PLATFORM_MICROSOFT = 3
TT_MS_ID_UNICODE_CS = 1
TT_NAME_ID_COPYRIGHT          = 0
TT_NAME_ID_FONT_FAMILY        = 1
TT_NAME_ID_FONT_SUBFAMILY     = 2
TT_NAME_ID_UNIQUE_ID          = 3
TT_NAME_ID_FULL_NAME          = 4
TT_NAME_ID_VERSION_STRING     = 5
TT_NAME_ID_PS_NAME            = 6
TT_NAME_ID_TRADEMARK          = 7
TT_NAME_ID_MANUFACTURER       = 8
TT_NAME_ID_DESIGNER           = 9
TT_NAME_ID_DESCRIPTION        = 10
TT_NAME_ID_VENDOR_URL         = 11
TT_NAME_ID_DESIGNER_URL       = 12
TT_NAME_ID_LICENSE            = 13
TT_NAME_ID_LICENSE_URL        = 14
TT_NAME_ID_PREFERRED_FAMILY   = 16
TT_NAME_ID_PREFERRED_SUBFAMILY= 17
TT_NAME_ID_MAC_FULL_NAME      = 18
TT_NAME_ID_CID_FINDFONT_NAME  = 20

_library = None
def ft_get_library():
    global _library
    if not _library:
        _library = FT_Library()
        error = FT_Init_FreeType(byref(_library))
        if error:
            raise FontException(
                'an error occurred during library initialization', error)
    return _library
